Overview

Teaching: 20 min
Exercises: 20 min

Questions

How do you get started with versioning using Git on your own computer?

Objectives

Cloning a remote repository to your local computer

How to record (commit) changes

Publish and push changes from your local computer to the repository on the web

Inspecting changes before they are committed

Browsing changes

About this episode

We will practice cloning a (remote) repository, and (using GitHub Desktop), committing changes to it, browsing the changes, creating branches, and more. Doing this, we introduce some new concepts:

There will be two copies of your repository: that on your computer (local), and that on GitHub (remote). The action to create a local copy is called cloning.

We introduce the concepts of pull to move code GitHub→local, and push to move code local→GitHub.

Step 1: Create a clone (copy) of remote repository

In this exercise, we will download the repository we created in the previous episode, so that we can work on it locally instead.

Go to your remote GitHub repository via the browser. Click on the green Code button and select Open with GitHub Desktop.

clone-remote

In GitHub Desktop app, verify that the local path is where you want the repository to be, click on Clone in the appearing window:

clone-locally

After GitHub Desktop has created the local copy of the remote repository, we can open it in an external editor, such as Visual Studio Code.

Step 2: Create a new branch

In this exercise we will create a new branch to work in.

In GitHub Desktop app, click on Branch in the menu on the top and select New Branch:

branch-menu

Name the branch input-file and click on Create branch

Notice that the current branch now has changed from main to input-file.

At the moment, this branch is only in your local repository. In order for it to be seen also remotely, click on Publish branch.

branch-publish

Step 3: Add a file locally

In this exercise we will add the input file(s) mentioned in the analysis recipe, samples_openrefine_lesson.csv and data_cleaning_script.txt (optional), to our newly created branch.

First, download the samples_openrefine_lesson.csv (right click and ‘Save as’), and put it in the folder analysis-recipe (in my case it is in C:\Users\yvonne.kallberg\GitHub\analysis-recipe).

Go to GitHub Desktop, notice that the file name is there (to the left) with a green plus (meaning that it is a new file), as well as a preview of the file content (to the right):

csv-stage

Write a commit message (down to the left) and click on Commit to input-file:

csv-commit

In order for the file to appear remotely, we need to Push, either by clicking on Push origin in the top menu, or by clicking on Push commits to the origin remote:

csv-push

Optional

Repeat the process for the script file data_cleaning_script_openrefine_lesson.txt.

Step 4: Create a pull request

In this exercise, we will do a pull request and merge the branch we have committed the input files to, input-file, with the main branch.

First let’s inspect what we have on the remote repository. Via the browser go to your analysis-recipe repository.

Switch branches between main and input-file, and notice that the content differs between them (in the branch input-file there is a file, samples_openrefine_lesson.csv, which is not found in the main branch):

We could do a merge here, via the browser, but let’s try another way, using the GitHub Desktop app.

In GitHub Desktop, click on Preview Pull Request:

The appearing window let’s you know what the intention is, i.e. ‘Merge 1 commit into base: main from input-file, what the changes are (added file samples_openrefine_lesson.csv), and if this will cause any conflicts (answer: ‘Able to merge’):
Click on Create pull request. This will open a new tab in your browser, in your remote GitHub repository. Click on the green Create pull request button.

Notice that you now have a ‘1’ at Pull requests in the menu:
Further down on the page, there is a green button Merge pull request, click on that, and then on Confirm merge:

The last thing we need to do is some clean up, i.e. to delete the now merged branch ‘input-file’ since we don’t need it anymore. We could delete the branch via the browser, by clicking Delete branch:

branch-delete

However, this would only delete the remote branch, not the one we have locally. Instead let’s return to the GitHub Desktop app.

In the menu at the top, click on Branch and select Delete. In the window that then shows up, make sure that the branch is input-file and click the box Yes, delete this branch on the remote.
Finally, click Delete:

Note: There’s no harm in keeping merged branches, especially when they are only a few, but imagine that you have 20 or more branches, then it starts to get messy. ____

Extra exercise - starting locally from scratch

Up until now, we have started remotely on GitHub with creating a repository, and then adding content either by staying remotely or working locally via GitHub Desktop. However, imagine the scenario where you already have a file or a folder, and then realise that it would be a good idea to create a GitHub repository, and start with version control.

Say that we want start with version control on the folder with the Famous_project_No-1!.zip from the Data organisation practices module. I have extracted all the files and put the folder on my Desktop (C:\Users\yvonne.kallberg\Desktop\Famous_project_No-1!). Following the steps below, we can start with version control.

Step 1: Create new local repository

First we need to create a new local repository.

Open GitHub Desktop app, click on File in the top menu and select New repository.
Fill in the information and click on Create repository:

Step 2: Add the files to local GitHub repository

Next, we need to move the content from our folder on Desktop to our newly created GitHub repository, i.e. the files in C:\Users\yvonne.kallberg\Desktop\Famous_project_No-1!\ should move to C:\Users\yvonne.kallberg\GitHub\Famous_project\. I do this in File Explorer.

Step 3: Commit the files to local GitHub repository

Now, open GitHub Desktop app. Notice that we now have a whole bunch of new files.

Write a commit message and click on Commit to main:

Step 4: Publish the local repository to remote GitHub

So far, we only have the files locally on our computer. Hence, we need to Publish your repository to GitHub.

Click Publish repository either in the top menu or in the main window:

Done! Now you can continue working with this folder in a version controlled manner, creating branches, pushing to and pulling from remote repository, merging branches etc.

Summary

With GitHub Desktop, we can do everything we can on the web, but it’s more integrated. The most important concepts are that of remotes (links between repositories), pushing, and pulling.

We don’t cover it in this workshop, but you can eventually do all of these things from the command line, for example git commit some_file.csv. Once you are doing many things, this can be faster. Still, there’s almost always a place for applications like the GitHub Desktop and other graphical user interfaces/desktop apps to make things smoother.